[TR] camber specifications TR4

[pethier at comcast.net]

From: "Jeff W. Kimbrell" <kimbrelltr4 at yahoo.com>
> I own a 1962 TR4. The specification for the camber on the front end is listed as 
> 2 degrees positive in the repair manual.

Yes, to match the camber pull of the the toe-in.  Give a nice, stable steering on the highway.

> However I have noticed several parts 
> offered which can give you a fixed, or adjustable negative camber setting . 

Interesting.  Where did you see this?  Most parts I see are for the TR4A and the cars that followed.

>  My 
> question is if there is a handling advantage in changing from the stock 
> specification to the negative setting ?

Absolutely.  Positive camber is awful for cornering.  The concept is that you want to use the whole face f the tire tread evenly.  This means that the dynamic camber (the camber that you have on the outside wheel while actually cornering) should be zero or a bit negative. 

An unequal-length upper/lower wishbone suspension is designed to make the camber go more negative as the car leans.  This effect is measured by a "camber curve".

The camber curve on a TR4 is not going to go negative enough to cancel out both the positive static camber and the tilting of the chassis.  A big front swaybar helps (and has the added happy effect of nailing down the inside front wheel), by lessening body roll.

If you start with a negative static camber, you can tune the car to have an optimal dynamic camber.  You want to match that negative camber with a bit of toe-out to lessen tire wear on the highway.  You steering will not be the solid, stable setup that was designed-in, but a darty responsive type ideal for autocrossing but more tiring on long freeway drives.

These camber parts are not likely to be legal for Vintage Triumph Register stock-category autocrossing, but the sway bar is...


--
Phil Ethier West Side Saint Paul Minnesota USA
62 Triumph TR4 CT2846L, 07 Saturn Ion 3 2.4, 93 Suburban, 94 Miata C-package, 79 Caterham 7
pethier [at] comcast [dot] net http://forum.mnautox.com/forums/ http://www.flickr.com/photos/pethier